Automatic clutch



4Aug. 17, 1937.

J. E. PADG ETT AUTOMATIC CLUTCH Filed Sept. 26, 19

,'53 2 Sheets-Sheet 1 Josep/7 E Paczye/z Aug. 17, 1937. J. E. PADGETTA2,090,265 f AUTOMATIC CLUTCH Filed Sept. 26, 1933 2 Sheets-Sheetl 2Patented ug. I7, 1937 Automatic Drive ,& Transmission Company,Gloucester City, N. J., a corporation of New Jersey ApplicationSeptember 26, 1933, Serial No. 691,065

Claims.

The present invention relates to lmechanisms for automaticallytransmittingpower from a driving shaft to a driven shaft when therespective speeds of the shafts are properly correlated for 5 eiiicientoperation.

More particularly, the present invention relates to automatic clutchmechanisms, and although they possess operating characteristics andstructural features that render them especially useful in automotive orlike drives, they may be employed in a wide variety of powertransmitting drives. 'Ihe present invention also embodies many featuresthat may be advantageously employed in manually operable clutchmechanisms and therefore the following description and claims areintended to embrace manual as well as automatic clutch mechanisms.

The use of friction clutches in the drive mechanisms of motor vehiclesis universal, and in fact 20 many of them are of the single plate type,i. e.,

friction clutches wherein a driven disc or plate is disposed between,and frictionally cooperates with a pair of driving members. Theseclutches have proved to be fairly eillcient and durable in practice, andin view of their wide-spread adoption, they undoubtedly represent agreat improvement over the friction clutches that existed before theirdevelopment. y

Heretofore, when it has been desired to increase the torque handlingability of such clutches, theI plate or disc diameter has been increasedso as to increase the frictional engaging area thereof, or the drivingpressure applied to the plates has been increased, and in. someinstances both of these expedients have been resorted to with this endin view. Both of these methods ofnincreasing the capacity of suchclutches have their disadvantages however, as increasing the diameter ofthe plates necessitates a corresponding increase in the overalldimensions of such clutches, with the result that they are renderedbulky, and in some instances the limited space available in the driveinvolved has prohibited their use in such drives. 'Increasing thedriving pressures also is distinctly a disadvantage because itmaterially increases the pedal pressure required to declutch suchmechanisms. v

It has also been proposed to provide friction clutches with a pluralityof driving and driven plates, to thereby increase the frictionalengaging area of such clutches and correspondingly increase theircapacity, but such clutches have not proven to be entirely satisfactoryin practice, for the reason that they are expensive to produce; they areconstructed of a multiplicity of parts .replacing a single plate or discclutch; and the which are not interchangeable, thus rendering servicingthereof difficult; they require extensive modification of the drivemechanism in whichV they are being installed, especially when they areplates or discs thereof do not promptly free themselves when drivingpressure is relieved, with the result that` the clutch drags and thedriven shaft continues to be driven after the clutch has been released.

The present invention is particularly concerned with the production offriction clutches of the multiple plate or disc type which are free fromthe objectionable features above described.

Itis accordingly a primary object of the present 15 invention to devisemultiple plate clutches which are durable andhighly efficient inpractice; and yet which may be produced by lowcost, quantity productionmethods.

It is another major object of my invention to o i devise multiple plateclutches which will smoothly H establish driving connection betweendriving and driven shafts when their plates are forced together, and,which will completely disengage or release the plates when the drivingpressure is 2'5 withdrawn.

Another important object of my invention is to devise, for use infriction clutch mechanisms,- a novel pressure applying and frictionalunit, which `may be secured to a flywheel or like driv- 30 ingmember t'oconstitute a single plate clutch, and which may be secured to a spacingmember carriedby a flywheel or like driving member to form a multipleplate clutch. vA further object of the present invention is to 35 devisesingle plate and multiple plate clutches in which the majority of theirbasic structural elements are identical in shape and size, therebychangeable. o' 40 My invention further aims to devise a. novel frictionclutch unit, having a frictional member and speed responsive means forapplying clutch engaging pressures thereto in response to rotationthereof, which may be secured to different types 45 of supportingrotatable members to thereby form a single plate automatic clutch, or amultiple plate automatic clutch, depending upon the character of thesupport.-

A still further object of the present inventionois 50 to devise apower-transmitting mechanism, having two major elements, whichconstitute a friction clutch and which are so designed that they may bemodified to form either a single plate clutch or a multiple plateclutch. 55

v providing clutches whose parts are readily inter- My invention furtheraims to design multiple plate clutches so that the heat generatedtherein through slippage of the plates may be rapidly dissipatedAthrough radiation and convection.

Further objects of the present invention lwill become apparent as thespecification proceeds in connection with the annexed drawings, and fromthe appended claims. In the drawings:-

Figure 1 is a longitudinal sectional view of a clutch mechanism formingpart of my invention.

Figure 2 is a View of the clutch shown in Figure 1 as it appears whenviewed from the rightl5 hand side of that figure with the throwoutmechanism removed and with certain parts in section to more clearlyillustrate -the structure involved,

Figure 3 is a fragmental sectional view of the clutch mechanism shown inFigure l and it illustratesthe manner of mounting the hold-back anddriving pressure springs in the mechanism. Figure 4 is a fragmentalsectional view of the clutch shown in Figure 1 and it illustrates one ofthe automatic weights disposed in its engaging or outermost position,and the plates automatically engaged.

Figure 5 is a fragmental sectional view of the clutch shown in Figure 1as it appears when provided with a modif-led form of clutch` cover platesupporting member, also forming part of` the present-invention. A

Figure 6 is a fragmental sectional view illustrating the clutch coverassembly shown in Figure 1 as being applied directly to the flywheel.

Figure 'l is a fragmental sectional view of the clutch shown in Figureland it illustrates an adjusting mechanism associated with theintermediate plate.

Referring to the drawings, wherein like reference characters refer tolike parts throughout the several views thereof, my automatic clutchmechanism is preferably enclosed in a clutch housing that is illustratedas broken away for the most part, and it is designated by the referencecharacter I.

A driving shaft 3 is adapted to have rotational efforts applied to it bya suitable prime mover in any desired manner, and I'may constitute lthecrank shaft of an internal Vcombustion engine.

The end of shaft 3 is secured to a flywheel 4-by bolts 5, or in anyother suitable manner. Bolts 5 extend through aligned apertures in theilywheel and a flange provided on the end of shaft 3, and have nutsturned thereon.

Shaft 3 is further provided with a bore 8 in which is carried a bearingassembly 1 for supporting the reduced end `8 of a clutch shaft 9. 'I'herear end of shaft 9 is adapted to be journalled in a bearing assembly(not shown) that is preferably located in recess IIlvin housing I.

A hub II is splined upon shaft 9 and is pro-` vided with -a flange I2.operatively secured to flange I2, by. means of-rivets or the like, is avibration dampener designated generally by reference character I3 whichprovides a resilient driving connection between hub II and a driven discI4. This vibration dampener is employed to'dampen out any torsionalvibrations that may be set up in the crank shaft of the engine, and inview of the fact that it forms no part of the present invention, it willnot be further described.

Facings I5 and I 8 are secured to opposite sides of disk I4 near itsperiphery, and they may consist of any material that has the requiredcharacteristics to give the correct frlctional gripping force, and atthe same time has wearing qualities adapting it for this purpose. Iprefer, however, to use the types of material which in practice havegiven very satisfactory results in` automatic slippingl drive and clutchmechanisms of the "Powerf1o type. Frictional facings I5 and I8 may besecured to disk I4 in any suitable manner, as for instance by rivets orthe like, and they, along with disk I4, will be hereinafter referred 'toas the driven member. Facings may be annular disks, or they may beformed as segments and secured'to disk I4 in circularly spaced relation,in order to provide a flow of cooling air currents if desired.

Facing I5, secured to disk I4, cooperates lwith the at driving face offlywheel 4 and is adapted to be frictionally driven thereby. Facing I8,cooperates with a plate I1, which will be hereinafter termed theintermediate plate, and it is adapted to engage and clamp the drivenmember between it and the-'fiat face of the ywheel. Plate I1 is ofsubstantial thickness so that it may possess a suflicient degree ofy.rigidity to prevent undesirable distortion and warpage thereof underthepressures and temperatures that it is subjected to during operationof the mechanism.

Intermediate plate I1 is driven by the fLvwheel through the intermediaryof driving lugs I8, which are preferably three in number and areintegrally formed with plate I1. Lugs I8 are disposed in slidingengagement with the walls of recesses I9 which are formed in rim portion2| of flywheel 4. Each lug I8 is provided with a recess 22 into which isfrictionally fitted a sleeve 23. comparatively light compression springs24 are disposed in;l sleeves 23 and act against the flywheel so as toforce plate I1 away therefrom.

Although I prefer to associate springs 24 with lugs I8, it is to beunderstood that they may be located in anyi otherl suitable positionwithout departing from the spirit of the present invention.

Movement of plate I1 away from the ywheel is limited by engagement ofboss portions 25,

formed on lugs I8 thereof, with a cover member Cover member-28 issecured `to thev flywheel rim portion 2I by means of cap screws 21, andit is provided with embossed portions 28 in the regions of cap screws21, for the purpose of spacing the cover from the flywheel rim for apurpose that will presently appear.

Cooperating with plate I1, and with an automatic plate 29, is al seconddriven member, comprising a hub 3|; a vibration dampener 32 and a drivendisc 33, carrying facings 34 and 35. Secured to theinner walls of cover28, by means of a spot welding operation or the like, are threesymmetrically arranged lug or key members 38. Key members 38 arereceived in, and cooperate with the walls of recesses 31 formed inautomatic plate 29 to establish a driving connection between flywheel 4and the automatic plate.

Disposed parallel to plate 29 is a plate 38, and it will be hereinafterreferred to as a. reaction plate, because it takes the reaction of thespeed responsive mechanism in a manner to be presently described.Reaction plate 38 is driven by to prevent the cap screws from workingloose in operation. Cap screws 39 extend through, and lie in slidabledriving engagement with the walls of recesses 42 formed in reactionplate 38, and 5 are encircled by washers 43 and compression springs 44.Springs 44 act against the heads of screws 39 and react against plate38, to thereby urge the automatic and reaction plates toward each otherat all times, and they will be hereinl after referred to as holdbacksprings. The holdback spring assemblies are preferably symmetricallydisposed in pairs about the periphery of the plates and in the presentinstance six are employed, but it is to be understood that more or lless than six properly designed holdback spring assemblies may be usedif desired without in any way departing from the spirit of my invention.The hold-back assemblies accordingly establish a driving connectionbetween the automatic and reaction plates, and, at the same time,resiliently urge the latter toward each other.

Reaction plate 38 is normally urged toward the flywheel by a pluralityof compression springs 45, which are retained in position against plate3B by means of bosses 46 formed on the latter. Springs 45 react againstthe surface of `cover 26, and are centered thereon by means of pressedout portions 41 formed in cover 26. Springs 45 I are preferably six innumber and are disposed in substantially common radii with the'holdbackassemblies. Reaction plate 38, however, is normally held in the positionshown in Figure 1, when the driving shaft is operating at or below theidling speed'of the engine or other prime mover, by means of a throwoutmechanism that will presvently be described.

Before proceeding to the description of the actuating mechanism for theautomatic plate, it should be understood, vthat although I have il- 40lustrated the surfaces that' engage facings 5 and |6 as plane inconfiguration, they may be grooved in the manner shown in my copendingapplication Serial No. 669,766, if desired.' The automatic and reactionplates may be actuated away from each other by any-suitablespeed-responsive mechanism,l to produce clutch engagement, but in the`present embodiment of my invention, it preferably takes the form of acentrifugally operable mechanism. Preferably three weight levers 5|,having integrally formed heads 52, are symmetrically' arranged betweenthe pairs of pressure springs 45, and have their heads' 52 received inrectangular recesses 53 formed in automatic plate 29. Each lever 5| isprovided with a pair of threaded portions 54, which are received in apair of apertures 55 located in a weight element 56. A

reinforcing `portion 51 is preferably formed on each lever 5|, and isprovided with a flat surface 59 that is adapted to abut the surface ofweight 56. Weights56 are held in place on levers 5| by means of nuts 6|,turned on portions 54, and seating in countersinks 62 formed in weights56 65 lievers 5| are of substantial width and extend through recesses63. formed inl reaction plate 38. Heads 52 are provided with flat faces64 that normally abut the bottoms of recesses` 53 when the driving shaftis operating at, or below idling 7 speed, and by the term idling speed,I'mean the particular desired automatic uncoupling or disengaging speedof the driven shaft, and if an internal combustion engine is employed astheA 75 prime mover, the idling speed will lie in the neighborhood offour hundred to five hundred revolutions per minute.

Heads 52 are also provided with reaction faces 66 which abut the face ofreaction plate 38 at all times, and are designed for fulcrum'mingengagement therewithA during operation of the weights. The surface ofplate 38 that cooperates with faces 66 of weight-he-ads 52 may, ifdesired, be groundv and polished so that relative sliding movementthereof may occur with a minimum of friction.

Heads 52 have their outer sides relieved to provide knife-like edges 68which are adapted'to rock or pivot in the dihedral angles dened by thebottom and outer faces of recesses 53 formed in automatic plate 29. Therelieving operation enables a good knife edge 68'to be formed on eachweight head, and allows pivotal movement thereof without interferencefrom the outer side walls of recesses 53. However, it is to beunderstood that unrelieved weights may be employed in recesses that aresuitably designed so as to have relieved outerside walls, if desired. Itis also to be understood that, instead of providing individual recesses53 for cooperation with the weight heads, a single annular groove, asshown in my co-pending application, Serial No. 660,179, filed March 9,1933, may be formed in automatic plate 29 if desired, without departingfrom the spirit of the present invention.

Recesses 53 are formed in automatic plate 29 in any desired manner, asfor instance by a milling cutter or the like, and Weight heads 52 areprevented from moving longitudinally within the recesses so formed, bythe engagement of the walls of recesses 63 formed in plate 38, with thesides of levers 5|. Heads 52 t rather snugly between the inner and outerside walls of recesses 53 so that they are restrained from shiftingbodily inwardly or outwardly, thereby insuring dynamic balance of themechanism at all times. Knife edges 68 are adapted to cooperate with theat bottom faces of recesses 53 and thereby act in line contact uponplate 29 for a substantial distance across the face thereof, wherebyuniform distribution of pressure oy'er a. substantial area thereof iseffected. Each weight 56 is further provided with recesses 69 which-allow free operation thereof without interference from springs 45.

The seats formed by the bottom and outer faces or walls ofrecesses 53constitute bearing recesses in which edges 68 of Weight`heads 52 areadapted to fulcrum.

Ihe mass of weights 56, `ancl the number of weights and lever assembliesemployed in a particular installation, is determined by a considerationof the required pressure that they must transmit under the desired speedconditions to urge the clutch plates into final non-slipping engagement.In the automatic drive clutch'mechanism shown, three equally spacedweight assemblies are preferably employed. v

When shaft 3 is stationary, or is operating at, or below a speedcorresponding substantially to the idling speed of the prime moveremployed to drive it, the parts assume the positions in which they areshown in Figure 1. Heads 5l of levers 5| are clamped between plates 29and 38, under the influence of springs 44 acting against plate 38 andcap screws 39, .md plate 38 is held in the position shown, against theaction of springs 45.by means of a throwout mechanism that will bevdescribed hereinafter.

Extending throughv apertures 1| formed in plate 38, and preferablysymmetrically disposed between the weight assemblies, are a plurality ofbolts 12. Bolts 12 are provided with knurled 5V portions 13, and aredriven into plate^38 and serve to hold bolts 12 against rotation. Castlenuts 15 are threaded on vbolts 12 and are adapted to be held in adjustedpositions thereon .by means of cotter pins 16. Hardened washers 11 aredisl0 posed onbolts 12 and cooperate with clutch fingers 18 to producemovement of plate 38 away from the flywheel. Fingers 18 are pivoted onroller or needle bearings 19 journalled on pins 88 secured in spacedears 8| formed on bracket meml5 bers 82. Pins 88 are preferably held inposition in ears 8| by means of cotter pins 83, and brackets 82- aresecured against pressed in portions 84 of cover 26 by means of Irivets85 or the like. Fingers 18 are provided with bifurcated portions 86, and20 the latter have curved faces 81, thatcooperate with washers 11 in'amanner to be presently der scribed. Bolts 1,2 are also encircled bylight compression springs 88 and Washers 89' and the latter are urgedinto contact with levers 18 to hold the latter against rattling whenthey are not under the influence of springs 45.

Bolts 12 and nuts 15 are adapted to partially extend through apertures89 formed inrcover 26, and the apertures are preferably of a sizesufficient to allow a wrench or the like to be applied to nuts 15 forclutch adjustment purposes.

Levers 18 are provided with weight or mass portions 98, which functionto balance the levers` and prevent them from responding to centrifugalforce and tend to impart declutching movements to the clutch parts.

Movement of the'inner ends of fingers 18 to the left, in Figure 1,through the intermediary of bolts 12,'causes movement of plate 38 awayfrom 40 the flywheel against 'the action of springs 45. Movement of thereaction plate produces similar movement of plate v29 because theholdback as-l semblies hold the two plates in unitary relationship atall times. Fingers 18 are adapted to'be actuated in this manner by meansof a throwout assembly that will now be described. y Cooperatingwithcurved faces 93 formed on ngers 18 is the flat face of a ball race 94,which cooperates with anti-friction balls 95 disposed between race 94and a cooperating ball race 98.

Ball races 94 and 96 are held in assembled relation with respect to eachother by means of a combined retainer and reservoir deningmember SI1.Ball race 96 is rigidly mounted upon a sleeve 98 which is slidablymounted upon a hollow supporting member 99. The latter is preferablysecured to housing I by. means of cap screws |88 and is accuratelyassembled to be disposed in axial alignment with the clutch mechanismand primel mover shaft 3 when the clutch is assembled, and is designedto provide a close sliding fit with sleeve 98. Member 99 is preferablyspaced substantially from, and is independent of, shaft 9. Sleeve 98 isprovided with a tapped bore |82 into which a grease fitting |83 of wellknown construction is screwed. Bore |82 communicates with an axiallyextending passage |84 formed in sleeve 98 so that lubricant introducedthrough 'bore |82 provides` lubrication Ifor axial movements of sleeve98 and also provides lubrication for the bearing assembly through apassage |85 communicating `with passage |84 and reservoir definingmember 91 associated with the bearing assembly.

-Sleeve 88 is prevented from` rotating about amazon support 99 by meansof an apertured lug |86 formed on sleeve 98. A stud |81 is slidablyreceived in lug |86 and is threaded into an aperassembly in connectionwith my invention, it is to be understood that any suitable throwoutmechanism having a face that is substantially normal to the clutch axisfor cooperating with the inner ends of fingers 18 may be employed ifdesired, and a thoroughly practical mechanism obtained. t

- With reference to the automatic and reaction plates, it is observedthat they are keyed together, or connected together for synchronousrotation by means of the holdback assemblies, and reaction plate 38 isin fact carried by automatic plate 29. Weights 56 are also carried bythe automatic plate, and as this weight and plate organization is ofcomparatively great mass, movement thereof radially, or in any directionother than .parallel to the axis of the mechanism,`results in static aswell as dynamic unbalance thereof, and as a matter of fact, it has beenfound in practice that for the clutch mechanism illustrated, a radial orsidewise movement of four one-thousandths of an inch of these elementsrepresents approximately two inch-ounces tending to unbalance themechanism.

In order for the plate and weight assembly to function properly, it mustbe capable of undergoing free axial movement. By designing driving lugs36 and recesses 31 so as to provide suilicient play to permit. thisaction, sufficient lost motion is usually introduced into the plateorganization to permit it to undergo a slight radial movement, and thisresults in the unbalanced condition just described.

In orde lto eliminate this difculty, the plate and weight organizationis so designed, that it is in substantial or complete static and dynamicbalance when the automatic plate is located on one side of themechanism, i. e., with the walls of recesses 31 in close contact withtwo of the I driving lugs 36, and means are provided for maintaining theassembly in this condition during all phases of operation of themechanism, with the result that it is balanced at all times. Thespecific form of means for producing this result may take any formdesired, but in the present embodiment of my invention, it `consists ofa bowed leaf spring having an aperture ||2l which fits over and is heldin place by one of the driving lugs 36. In view of the simple design ofthe present clutch mechanism, the parts thereof may be manufactured bylow-cost, quantity production methods, and yet provide plate and weightorganizations whosemass is fairly symmetrically distributed. However. Iprefer to compensate for i unbalance of the parts by mechanism locatedexternally of the clutch, in the manner to be hereinafter described, sothat it may be balanced after it has been assembled.

In view of the fact that spring exerts a frictional resistance againstonly one side of plate 29, engaging anddisengaglng movements of thelatter axially of the mechanism are yieldingly resisted or retarded tosomeextent, which may lthough I have disclosed a specific throwout` 5Jthereof.

three symmetrically arranged balance assemblies result inthe automaticplate tilting slightly as itundergoes movement into and out ofengagement with facing 35. This is an advantage rather than adisadvantage, however, because the slight 5 tilting action which takesplace is not sufficient to unbalance the mechanism, especially at thecomparatively low speed at which engagement occurs, and the resultinginitial partial and progressive engagement of automatic plate 29 with.10 facing 35, as weights 56 rock outwardly, imparts extremely smoothoperating characteristics to the mechanism and gives a cushion disc"effect. When the clutch is fully engaged, the plates are not tilted, butare disposed parallel to each other and normal to the axis of themechanism, so that the mechanism does-not vibrate, even at high speeds.

In the particular clutch mechanism illustrated, spring III preferablyexerts a force of approximately thirty pounds, and is designed to urgethe automatic plate toward the other lug assemblies and serves to takeup the play or lost motion. therein. Spring III acts against and appliespressure to portions I I3 of plate. 29, located either side of recesses3l. Spring III accordingly maintains the parts In balanced condition atall times, and yet, in view of its resilient nature, it doesnotinterfere with free axial and slight tilting movements 'of automaticplate 29. Although I prefer to employ a spring of the type disclosed forholding the-parts in balanced condition, it is to be understood that atension or compression spring, or any other suitable means, may beemployed to produce this result, without departing from the spirit' ofthe present invention.

In order toprovide dynamic and static balance of the mechanism asawhole, I provide balance assemblies which are preferably secured .to theouter cylindrical portion of cover 26,' and they are preferablysymmetrically located between the vweight assemblies or radiallyoutwardly beyond levers 18. Eachbalance assembly preferably' consists ofa pair o f main Aor principal Weight members IIS, which take'the form ofwashers; and a plurality of auxiliary weight members IIB which consistof small washers in the present embodiment of the invention; which areheld in Iplace' by means of a bolt I Il, passing through an aperture `incover 26, a n-ut I I8' and a lock washer II9.` The mass of the balanceassemblies depends upon the nature of the particular clutch mecha-V nismand the dimensions and mass of theiparts In the particular clutchillustrated,

of the size shown are employed and their mass is such as to offset theconcentrated mass represented byv the weight assemblies and render theo0 mechanism both statically and dynamically balanced. In the event thatafter the balance assemblies are applied to the mechanism, the latter isstill out ofv either static or dynamic balance or both,v because ofunsymmetrical mass distribu- 65 tion caused by manufacture of the partsby low'- cost, quantity production methods, one or more washers II9 maybe removed from or added to one or more of the balance assemblies tobring about proper balance of the mechanism. 70 The provision of thepresent balance mechanism materially reduces `the cost of producingclutch mechanisms ofthe manual or automatic type because their partsmaybe cheaply made without regard to their mass or dimensions, and 75if, upon assembling the mechanism, it is found that it is out ofbalance, either statically or dynamically, it can be readily broughtinto balance in the manner just described.

It is also to be understood that the use of -the balance mechanism justdescribed, as well as the 5 balance spring employed to yieldinglyposition the automatic plate, is not limited to the particular type ofautomatic clutch illustrated, and that they may, in fact, be employedfor balancing manually operable clutch mechanisms.A 10

.Clutch pedal shaft IIIl is preferably adustably held by a. suitablemechanism in such a position that the throwout bearing assembly willhold the parts in the positions in which they are shown in VFigure 1when driving shaft 3 isv stationary or is l5 operating at, or below, apredetermined idling speed of the prime mover utilized therewith. Underthese conditions, aA clearance exists between the plates and there isaccordingly no driving connection between shafts 3 and 9. Any suitable20 latch mechanism may be associated with shaft I I D or the clutchpedal for holding shaft I I0 in this position, but I preferably employthe type of clutch pedal latch mechanism disclosed in my -copendingapplication, Serial No. 660,179, led 2.5

March 9, 1933, and which may be referred to for a full disclosurethereof. The throwout bearing assembly is shown in Figure l in what istermed its automatic".vposition, and is so termed because it ispreferably disposed in this position 30 when the clutch mechanismfunctions, or is being employed as an automatic or speed responsiveclutch. If desired however, vacuum operated mechanisms of the type shownin my copending application, Serial No. 669,766 led May 6, 1933, 35 maybe associated with the throwout assembly for automatically actuating it,and the appended claims are intended to embrace my clutch mecha-'- nismwhen so equipped.

The clutch pedal may be depressed to move the 40 throwout bearingassembly to the left of the position shown in Figure 1, for manuallydeclutching the mechanism in a manner to be hereinafter pointed out, andthe parts 0f the latch mechanism are so designed to allow this move- 45ment of the pedal without interference.

The latclmechanism may be operated to allow the clutch pedal to retractand permit the throwout bearing to move to the right of the positionillustrated in Figure 1, into what is termed its 50 manually engagedposition.

With the throwout mechanism disposed in automatic position, the speedresponsive or automatic operation ofthe mechanism is as follows:

Automatic operation Acceleration of shaft 3 slightly above the idlingspeed of the prime mover does not cause actuation of the plates becausesprings M hold lthem in check. As driving shaft 3, and ywheel 4 areaccelerated to a. speed substantially in ex-i cess of idling speed,weights 55 gradually swing or rock outwardly about their knife-edges 68as axes in response to centrifugal force. As this occurs, reaction faces66 of heads 52 fulcrum and 65 slide on the face of plate 38 and knifeedges 68, and by virtue of their engagement and i'ulcrumming action uponthe at bottom surfaces of recesses 53 located in automatic plate' 29,they force the automatic plate away from reaction 70 plate 38 againstthe action of holdback springs 4l, and into engagement with facing 35 ofdisk 33, on a three-point support, thus causing disk 33 to move axiallyand bring the facing 34 thereof into contactwith inte ediate plate I1,which is then moved axially against the action of ref tractor springs24, and clamps driven member I4 between it and the ywheel.

Movement of automatic plate 29 away frm re- 5 action member 38 isopposed by holdback springs M, and therefore weights 56 are held undercontrol. Holdback springs 44, therefore, in addition to predeterminingthe speed of the mechanism at which automatic engaging operation isinitiated, exert a steadying influence upon the clutch parts.

After the driven members are thus frictionally clamped or grippedbetween automatic plate 29, the intermediate plate and flywheel 4,movel5 ment of plate 29 is substantially arrested, and

further rocking movement of weights 56, in response to a furtherincrease in centrifugal force, causes faces 88 of heads 52 to forcereaction plate 38 away from the flywheel against the action of springs45.' Movement of plate 38 in this manner causes pressure to slowly buildup in springs 45, and a corresponding pressure is built up between theedges 68 of heads 52, and the bottoms of the recesses in automatic plate29. This action causes the plate pressure to build up comparativelyslowly, with the result that the clutchl smoothly picks up the load.

It is observed that fulcrums 68 of weight heads 52 are disposedapproximately midway of the outer and inner peripheries of plates I1 and29,

and act in line contact therewith for a, substantial distance acrosstheir faces, 'applying substantially uniformly distributed pressuresopposite the center of their engaging or .working areas, therebyminimizing warping and distorting tendencies of the plates under thepressures and temperatures to which they are subjected during operation.

The partial vacuum established by rotation of 40 the parts causes an`air stream to be drawn through the relatively large annular passagebetween cover 26 and the throwout bearing and along the clutch axis. Apart of the axial air stream passes over both faces of plate 38 andbetween plates 38 and 29, and in this connection, it should be observedthat plates 29 and 38 are substantially thermally isolated, and the aircurrents passing between them effectivelyprevent the heat that isgenerated in plate 29, as the result of slipping, from being transmittedto plate 38, and possibly drawing or harmfully modifying the temper ofsprings M and 45 associated with the latter. Another portion of the airstream passes outwardly between plate 29 and facing 35 when they aredisengaged, and the heated, dustladen air is exhausted from themechanism through thespace between the flywheel and cover 26. Portionsof the axially moving air stream enter openings formed in discs Il and33, (not shown), and are discharged radially between the driven membersand the intermediate plate and fly-wheel, and are exhausted from thecover through openings |20 formed in flywheel rim 2|, and between cover26 and the flywheel.

The Ventilating and dust-removing air may be introduced into, andexhausted from housing I in any desired manner, but I preferablycontemplate the use of the organizations disclosed in application'SerialNo. 606,238, filed April 19, 1932,/which 70 have proved to beextremelyefhcient in practice.

Whenv shaft 3 and flywheel l attain a predetermined speed, weights 58rock out into contact v' with arcuatelyshaped stopl faces I2| formed onpressed flange portions |22 of plate 38, as seen 15in Figure 4. In orderto stop weights 56 in a definite plane that is normal to the mechanism,

and thus insure dynamic balance of the device, preferably arcuatelyshaped stop-edges or faces |23 are accurately formed on weights 56.'I'he stops are also designed` to stop weights 58 with their centers ofmass equidistant from the axis of the mechanism. When the weights havemoved into their outermost positions with their stop faces |23 incontact with stop faces |2I, the plates are disposed in non-slippingengagement and further acceleration of shaft 3 is ineffective to cause afurther pressure to be built up between the plates. The plates arethereby held in non-slipping engagementunder a predetermined pressure,and a positive friction coupling exists between shafts 3 and 9.

Stop faces |23 are so located on weights 55 that when the weights aredisposed in their outward positions in contact with ange |22, the centerof mass of each weight is disposed to the left of a vertical-planepassing through the point of Contact between stop face |2I in pressedflange |22 and stop face |23 on the weight, so that the.

centrifugal force developed in the 'weights is never effective to causeclockwise rotation of the weights about flange |22 as afulcrum, andhence the weights are prevented from exhibiting declutching tendenciesregardless of the rotational speed of the mechanism.

With reference to levers 18, they are designed so that, when the clutchis engaged, the masses thereof are so located with respect to theirpivots, that the centrifugal forces set up therein, as the result ofrotation of the mechanism, do not exert substantial rotative influences-on the levers. When the parts are disposed in automatic idling position(Figure 1) the greater portion of the masses of levers 18, is located tothe right of their pivots, but this is not a disadvantage. however,because the parts only assume these positions when the mechanism isrotating at low speeds, and the centrifugal forces existing under theseconditions are likewise of low magnitude.

When the clutch has been automatically engaged lin the manner justdescribed, the inner ends of levers 18 move away from the throwou'tassembly, and the inner endsof the levers are spaced a substantialdistance from the latter. This is brought about through movement ofreaction plate 38 to the right. and the levers are held in this positionunder the influence of springs ilsV so long as the clutch is in full,automatic engagement. Weight portions 80 are so related with levers 18,that when the clutch is automatically engaged, the centrifugal forcesset up in them, each side of a. plane normal to the axis of themechanism and passing through their axes, are approximately equal, sothat they will not under-.- so rotative tendencies. If levers 18, inresponse to centrifugal force, exhibited tendencies torotate so as tomove their inner ends to the left,

' the levers would transmit declutching forces to sembly in response tocentrifugal forces set up therein, such movement would be ineffective tomodify the plate pressure established by the action of weights 58,because faces 81 of levers 18 would merely move away from washers 11,against the action of springs 88. Therefore, the prime requisite is thatthe levers, in response to centrifugal force, will not exhibittendencies to move in such manner as to bring their inner ends away fromthe throwout assembly when the clutch mechanism is automaticallyengaged.

In view of the resilient nature of the backing means 4for the reactionmember, should certain 5 weights 56 swing further outwardly than theremaining weights, during theengaging operation, the pressure exerted bythem is nevertheless uniformly distributed between the segments of plate29 for' the reason that reaction plate 38 can tilt or oat, and take aslight angular position with respect 'to automatic plate 29, due to thefact that the sole movement limiting means of the reaction member isconstituted by bolts 39, and the latter are designed to provide suicientplay or clearance to permit this tilting action. The

throwout bearing assembly therefore only operates when the clutch isoperating at idling speeds or is manually declutched, and it thereforereceives only a minimum amount of wear and its life is therefore greatlyincreased.

With the above described mechanism installed in a motor vehicle providedwith a conventional three-speed transmission, and the. vehicle on asubstantially level surface, the transmission may be placed in high gearwithout operating the clutch pedal if the engine is operating below theengaging speed of the clutch mechanism, and the A engine may beaccelerated to produce automatic clutch engagement in the mannerpreviously described. During the engaging operation, a slipping driveexists between shafts 3 and 9 and the vehicle is accelerated smoothlyand without shock and in view of the speed-responsive engagingcharacteristics of the mechanism, it is impossible to stall the enginethrough improper actuation of the accelerator. When the engine andvehicle speeds are properly correlated, the clutch plates are broughtinto full driving-engagement, thereby automatically establishing adirect coupling between shafts 3 4and 9.

When loperating in this manner, and it is desired to decelerate or stopthe vehicle, the accelerator is released and the brakes are applied.When the vehicle has decelerated to a speed corresponding substantiallyto engine idling speed, through the combined braking action of theengine and the Vehicle brake mechanism, weights 56 rock inwardly underthe influence of hold-back springs 44, the plate assembly moves to theright (Figure 1), disengagement of the clutch plates is automaticallyeffected, and when lugs I8 of plate Il contact cover 26, plate I1 isarrested and disc I4 is relieved of driving pressure. Plate 29 thencontinues to move to the right under the influence of springs 44, untilweights 56 attain neutralposition, at which time driven disc 33 isrelieved of driving pressure. Accordingly shafts 3 and 9 are therebyautomatically uncoupled and the braking action of the engine is nolonger transmitted to shaft 9, but in view of the fact that thedisengaging speed of the clutch mechanism is usually fairly low, thevehicle is decelerated to a relatively low speed under the brakinginfluence of the engin-e before the mechanism automatically disconnectsshafts 3 and 9.

The vehicle .may then b e brought to a complete stop by continuedapplication of the brakes, or, if traflic conditions permit, theaccelerator may be depressed and the engine accelerated to producealmost immediate re-engagement of the mechanism and the vehicle againpicked up in high gear.

Due to its slipping drive characteristics, the 7;, present mechanismconstitutes a drive mechanism as well as a clutch, and while it does notmultiply the torque delivered from'shaft 3 to shaft 9, it permits theengine to operate at a higher speed, and consequently, at a higher pointon its speed-torque curve, and deliver more power, than if substantiallynon-slipping conditions existed between shafts 3 and 9, and thisfeature, in combination with the lubricated facings, the novel platestructure, and the self-cooling characteristics of the presentmechanism, renders it entirely feasible to operate vehicles in whichthey are incorporated in high gear under normal conditions.

As previously explained,v a latch mechanism is adjusted to hold theparts in the positions shown in Figure 1 of the drawings, when the primemover is operating at idling speed or is stationary. When the facingshave become thin, as the result of particles thereof wearing away duringoperation, and cause the idle release plate clearance to become toogreat, the throwout bearing assembly is moved slightly to the right ofthe position in which it is shown in Figure 1, by adjusting the latchpedal on its shaft, or adjusting the latch mechanism in any suitablemanner, in order to dispose intermediate plate I1 closer to the flywheeland establish proper plate clearance for idle release conditions. Incopending application', Serial No. 595,184, filed February 25, 1932,adjusting mechanisms are disclosed that have proved to be highlysuccess-A ful in practice, and I contemplate using these adjustingmechanisms in the present invention. When facing wear has beencompensated for several times, by periodically adjusting the throwoutbearing assembly further to the right, fingers or levers 'I8 may beallowed to move to the right to such an extent that, under someconditions, they take undesirable angular positions. This condition isreadily remedied, or compensated for, by adjusting. nuts 'I5 an equalamount, and

sufficient to bring levers 'I8 into the proper posi-- tions desired.'I'he external adjusting mechanism previously referred to may then bemanipulated to establish proper idle release clearance between theplates, and clearance gauges may beintroduced between the cover and theflywheel and inserted between facing I5 and the flywheel face toascertain if the plate clearance is correct. The normal plate wearcompensating adjustment, however, is made externally of the clutchhousing by adjusting the angular position of shaft IID into properautomatic position, and therefore this adjustment does not in any wayaffect the adjusted positions of nuts "I5, and consequently, the angularrelation of the plates. The excess release clearance which developsbetween driven disc I4, the ywheel, and the intermediate plate, may betaken care of by inserting shims` or the like between lugs I8 and cover26, or byany other suitable means.

Manual disengaging' operation ment of automatic plate 29 from the driveninember because plates 29 and 38 are held in unitary relation by theholdback assemblies. If the engine speed is maintained above thepredetermined engaging speed during the manual declutching operation,weights 56 remain in their outermost positions, therefore, thedeclutching operation does not involve retracting the weights againstthe action of centrifugal force, which, at high speeds might ybesufficiently high to preclude effecting the manual declutchingoperation.

In traffic, when it is desired to get the vehicle away quickly, and instarting up steep grades, the clutch pedal may be operated in thismanner to disengage the plates for gear shifting purposes as in avehicle provided with a manually operable clutch. The clutch pedal mayalso be operated to produce manual engagement of the plates (if theengine is operating above the' engaging speed of the mechanism) in amanner similar to a manual clutch, for maneuvering the vehicle into andout of parking positions or for navigating in heavy traflic.

Manual engaging operation As has been previously pointed out, when shaft3 is operating substantially at the idling speed of the prime mover, oris stationary, and the clutch pedal is latched to dispose the throwoutbearing in the automatic position shown in Figure 1, a clearance existsbetween the clutch plates, and shafts 3 and 9 are accordingly dis'-connected. When it is desired to establish a driving connection betweenshafts 3 and 9, under these conditions, the latch associated with theclutch pedal is actuated to allow the latter to move into its retractedposition. Retraction of the clutch pedal allows the throwout bearingassembly to move to the right under the influence of springs 45, and thelatter, acting against the reaction plate, bring reaction plate 38 andautomatic plate 2S to the left of the positionsin which they are shownin Figure 1, with automatic plate 29 in driving engagement with thedriven member, thereby coupling shafts 3 and 9. With the above describedmechanism installed in a motor vehicle, it is frequently desirable toeffect this manual engaging operation. 'For instance, when `Vthe motoris cold and the battery is low, it is desirable to place thetransmission in 50 gear and push or coast the vehicle to turn the engineover. Also when stopping on a steep grade,.positive engagement of theclutch, with the transmission placed in low or reverse gear, provides anemergency brake that cannot be in# 55 advertently released; or if themotor stalls, from lack of fuel or any other cause, the vehicle can pullout of dangerous positions by propelling it in low gear with thestarting motor.

The present clutch mechanism is designed to 60 be fully engaged Whenshaft 3 attains a. speed of approximately one thousand revolutions perminute, and as the Weights rock out into firm contact with their stopsat this time, the only speed at which the mechanism may possibly becomeunbalanced is below one thousand revolutions per minute (as for instanceby the weights moving' outwardly unequally), but at this comparativelylow speed, such unbalance, if it does mechanism. Above one thousandrevolutions per minute, where unbalance in the mechanism would possiblyresult in harmful vibration, it is maintained in accurate static anddynamic balance 75 by means of the balancing mechanisms, and an exist,does not result in harmful vibration of the extremely practical andeffective mechanism is thereby produced.

In Figure 5, I have illustrated a modified clutch mechanism wherein theparts are so designed that. a standard ywheel may be used to produce asingle or double plate clutch.

With continued reference'to this figure, iiywheel 4 is preferablyprovided with a plane face and secured thereto'by capscrews 21a is cover26 and preferably three arcuatemembers 2Ia,

flywheel and cover assembly employed in the single and double plateclutches illustrated are identical in character, and interchangeable, itis apparent that the two clutches may be manufactured cheaply, as it isonly necessary in order to produce a double plate clutch to assemblemembers 2Ia and an intermediate plate I1 with the standard flywheel andcover assembly.

.Although I have disclosed individual members 2Ia, it is to beunderstood that they may beintegrally formed, and be provided with slotsfor the accommodation of driving lugs I8, if desired, without departingfrom the spirit of the present invention. Moreover, as members 2Iafunction [primarily as spacing members, they may be formed and assembledin any other suitable manner other than that illustrated.

Referring now to Figure '7 of drawings, I have illustrated a modifiedform of mechanism for adjusting the intermediate plate.v In thisform ofmy invention, lugs I8 are adapted to cooperate with screws I3I which arethreaded into cover 26 and locked in adjusted position by means oflocknuts |32. The facing-wear compensating ad,

justment is preferably made by loosening locknuts I 32 and turningscrews I3I.so as to bring plate I1 closer to the flywheel. When theproper idle release clearance has been established, screws I3I arelocked in place by nuts |32. This adjustment has the effect ofincreasing the idle release clearance between plates I1 and 29, and thenext step in the-adjusting operation consists of actuating the externaladjustment previously described so as to establish proper clearancebetween plates I1 and 29.

Although I have disclosed, and prefer to employ clutch mechanisms of thedouble plate type, i. e., clutch mechanisms having three driving membersandtwo driven members, it is to be distinctly understood that myinvention -contemplates clutch mechanisms wherein -an increased numberof driving membersl cooperate with a correspondingly increased number ofdriven members to effect a driving connection between the driving anddriven shafts, and the appended claims are intended to embrace clutchmechanisms of this character.

It is to be also understood that although I have described shaft 3 asthe driving or power input shaft, and intend that power shall normallybe transmitted from shaft 3 to shaft 9, shaft 9 may be utilized as adriving shaft, and power may be transmitted through the clutch plates toshaft 3 if desired, for instance, in automatic'transmissions wherein thespeed responsive mechanism is accelerated suiliciently through low-speedgearing to initiate its operation, and the appended claims are intendedto embrace my novel clutch mechanisms when they are used in this manner.K f

'I'he invention may be embodied in other specic forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced ntherein.

' What is claimed and desired to b'e secured by United States LettersPatent is:-

1. In a friction clutch mechanism, a rotatable supporting structurehaving a frictional member carried thereby, a unit having a frictionalmember and pressure applying means associated therewith, at least onefrictional driven element disposed between, and being considerablythinner.

than said frictional members, means for securing said unit to saidstructure; means for spacing said unit a predetermined distance fromsaid supporting structure; said spacing means being of a dimensionsuilicient to permit lthe mechanism to function as a single plate clutchwhen re-assembled with the spacing member and certain other partsomitted.

2. In a clutch, a rotatable vsupporting member having an axiallydirected cylindrical ilange, a driving member having a plurality ofsubstantially radially disposed driving lugs provided therein, saidcylindricalflange being provided with a plurality of radially directedrecesses extending therethrough and having open ends, said drivingmember being disposed with said lugs seated in said recesses anddrivingly cooperating with the walls thereof, a clutch plate pressurecontrolling unit, provided with a cover having a radially directedflange, `secured to said supporting member flange with said radiallydirected iiange closing the opensides of said radially directedrecesses, said cover being disposed in the path of movement of, andadapted to be engaged by said lugs, to thereby limit movement of saiddriving member away from said ywheel, and a compression spring disposedin at least one of said recesses and acting against the bottom of saidrecesses-and reacting against one of said driving lugs and urging thelatter toward said mel'.

3. In a clutch mechanism, a rotatable supporting member having anaxially directed cylindrical flange, a frictional driving memberdisposed concentrlcally within said flange and mounted for rotation withsaid supporting member, the surface of said driving member remote fromsaid supporting member being disposed substantially in a common planewith the surface of said flange remote from said supporting member, africtional driven member disposed between said supporting member andsaid driving member, and a clutch plate pressure controlling unit havinga cover provided with a radially directed flange secured to saidsupporting member ange, said unit having a driving member mounted withinsaid cover for rotation with said unit, and a driven member mountedwithin said cover adjacent said driving member, the surface of saidlast-named driven member remote -from said last-named driving memberbeing disposed substantially in a common plane with said radiallydirected ange of said cover.

4. In a friction clutch mechanism, a rotatable supporting structurehaving at least one frictional driving member carried thereby, a unithaving at least one frictional driving member and pressure applyingmeans associated there-l with, frictional driven members interleavedbetween, and being considerably thinner than said frictional drivingmembers, means for securing said unit to said structure, means forspacing said unit a predetermined distance from said supportingstructure, said spacing means being of a dimension suflicient to permitthe mechanism to function with fewer frictional members when reassembledwith the spacing member and certain of said frictional members omitted.

5. In a clutch, a ilywheel or like supporting member having an axiallydirected cylindrical ange; a driving member having a plurality ofsubstantially radially disposed driving lugs providedthereon; said`cylindrical ange having a plurality of radially directed open-sidedrecesses provided therein, said driving member being disposed with saidlugs seating in said recesses and drivingly cooperating with the wallsthereof, a clutch plate pressure controlling unit secured to said angeand closing the open sides -of the recesses therein, said unit being sodesigned as to limit movement of the driving member away from saidywheel, said ange being detachably secured to said ywheel, whereby itmay be removed along with said driving member and the parts re-assembledto provide a single plate clutch. t

JOSEPH E. PADGE'II',

